package cn.com.assistant.config;

import cn.com.assistant.annotation.AdminLoginToken;
import cn.com.assistant.annotation.PassToken;
import cn.com.assistant.entity.User;
import cn.com.assistant.intercepter.TokenException;
import cn.com.assistant.service.UserService;
import cn.com.assistant.utils.TokenUtil;
import com.alibaba.fastjson.JSONObject;
import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTVerificationException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

public class AuthenticationInterceptor implements HandlerInterceptor {

    @Autowired
    private UserService userService;

    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) {
        String token = httpServletRequest.getHeader("Authorization");// 从 http 请求头中取出 token
        // 如果不是映射到方法直接通过
        if (!(object instanceof HandlerMethod)) {
            return true;
        }
        HandlerMethod handlerMethod = (HandlerMethod) object;
        Method method = handlerMethod.getMethod();
        //检查是否有passtoken注释，有则跳过认证
        if (method.isAnnotationPresent(PassToken.class)) {
            PassToken passToken = method.getAnnotation(PassToken.class);
            if (passToken.required()) {
                return true;
            }
        }
        //检查有没有需要用户权限的注解
        if (method.isAnnotationPresent(AdminLoginToken.class)) {
            AdminLoginToken adminLoginToken = method.getAnnotation(AdminLoginToken.class);
            if (adminLoginToken.required()) {
                // 执行认证
                if (token == null) {
//                    throw new TokenException(403, "无token，请重新登录");
                    try {
//                        httpServletResponse.sendRedirect("/user/noToken");
//                        return false;
                        httpServletResponse.setContentType("application/json;charset=utf-8");
                        Map m = new HashMap();
                        m.put("code", 500);
                        m.put("message", "用户信息失效，请重新登录");
                        m.put("data", null);
                        httpServletResponse.getWriter().write(JSONObject.toJSONString(m));
                        return false;
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                // 获取 token 中的 userId
                Integer adminUserId = TokenUtil.getAdminUserId(token);
                User adminUser = userService.findById(adminUserId);
                if (adminUser == null) {
//                    throw new TokenException(403, "用户不存在，请重新登录");
                    try {
//                        httpServletResponse.sendRedirect("/user/noUser");
//                        return false;
                        httpServletResponse.setContentType("application/json;charset=utf-8");
                        Map m = new HashMap();
                        m.put("code", 500);
                        m.put("message", "用户信息失效，请重新登录");
                        m.put("data", null);
                        httpServletResponse.getWriter().write(JSONObject.toJSONString(m));
                        return false;
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                // 验证 token
                JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(TokenUtil.SECRET)).build();
                try {
                    jwtVerifier.verify(token);
                    String attribute = (String) httpServletRequest.getSession().getAttribute(adminUser.getUsername() + "token");
                    if (token.equals(attribute)){
                        return true;
                    } else {
                        try {
//                            httpServletResponse.sendRedirect("/user/expireToken");
//                            return false;
                            httpServletResponse.setContentType("application/json;charset=utf-8");
                            Map m = new HashMap();
                            m.put("code", 500);
                            m.put("message", "用户信息失效，请重新登录");
                            m.put("data", null);
                            httpServletResponse.getWriter().write(JSONObject.toJSONString(m));
                            return false;
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                } catch (JWTVerificationException e) {
//                    throw new TokenException(403, "token不合法");
                    try {
//                        httpServletResponse.sendRedirect("/user/expireToken");
//                        return false;
                        httpServletResponse.setContentType("application/json;charset=utf-8");
                        Map m = new HashMap();
                        m.put("code", 500);
                        m.put("message", "用户信息失效，请重新登录");
                        m.put("data", null);
                        httpServletResponse.getWriter().write(JSONObject.toJSONString(m));
                        return false;
                    } catch (Exception exception) {
                        exception.printStackTrace();
                    }
                }
            }
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
        System.out.println("===============post");
    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
        System.out.println("===============after");
    }
}

